Thermostatically-controlled mechanism



4 Sheets-Sheet O. C. SCHROEDER THERMOSTATI CALLY CONTROLLED MECHANI S M.,

Filed Sept. 22, 1925 May 15, 192s.

O. C. SCHROEDER THERMOSTATICALLY CONTROLLED MECHANISM Filed sept. 22, '192s 4 sheets-sheet 2 May 15, 1928. v1,670.010

O. C. SCHROEDER THERMOSTTICALLY CONTROLLED MECHANISM Filed sept. 22, 1923 4 Sheets-Sheet. 4

I l j@ Patented May 15, 1928.v

OSQAB C. SGHROEIDER, F CHICAGO, ILLINOIS.

THEBMOSTATICALLY-CONTROLLED MECHANISM.

Application med September 22, 1923. Serial No. 664,307.

. My invention relates, more particularly, to "the thermostat element of thermostatically-operated .mechanisrrn my invention having been devised for embodimentmore particularly, though not. exclusively, -in burners. My primary objects are to provide a novel, simple and economical construction A of thermostat; to provide for the automatic plyingof the fuel to the burner is controlled,

the fuel in this instance being oil and the power device an electric motor, a description of -the accompanying drawings beingas Y follows Figure 1 is a .view in. elevation, partly sectional, of an oil' burner embodying my improvements. Figure 2 is an enlarged view in vertical sectional elevation of in y improved thermostatl and certain of -the parts controlled thereby, the thermostat-o erating in connection With the pilot ligt for the' burner, and the parts beingsliown in a position in which the supplying of fuel to the burner is arrested. Figure 3 is a section taken at the line`-v 3 on Fig. 2 and viewed in the directionof the arrow. Figure 4 isl a view likeFig.- 2`.showing the parts in the position they assume in the maintaining of the supply of fuel to the burner.' Figure 5 is a section taken at the line 5 on F ig. 4 and viewed 'in the direction of the arrow. Fi re 6 is a section taken at the 'line 6 on Fig. 4 and viewed in the direction of the arrow; and Figure 7, a view VAin sectional elevation of a furnace Iembodying my invention.

Referring to the particular illustratedv in` stallation in connection withwhichmy improvedthermostat mechanism is employed, the'burner proper, represented at 7, is shown' as mounted in the bottom wall 100 of a furnace 101 in position to extend at its upper end into the combustion chamber 102 of the 'furnace and discharge the fuel into the latter. The burner shown, which is vof a type well known in the art, employs' oil as the fuel the supplying. ofwhich to the outlet of the burner, froml any suitable source thereof through a pipe 8, is controlled by an electric motor 9.

Located adjacent to the burner structure referred to and in an opening 103 in ,the bottom Wall 100 is a pilot light structure which discharges into the combustion chamber 102 and is provided for igniting the fuel issuing from the burner, this pilot light structure fbeing represented generally at 10 and shown as involving a tubular member 11 carried by the main bodyV of the burner and surmounted by a-hollow cap 12 containing an opening 13 in its top, and a gas outlet tube 14communicating at its lower end with a gas passage 15 in the upper portion v of a hollow supporting member 16 shown as supported at oppositely-facing slots 17 on headed vstuds 19 secured to, and depending from', outwardly-directed lugs 20 on the tubular member 11, the passage 15 communicati'ng with a pipe 21 which leads to any suitable source of gas supply, as, for example, the vordinary service-.supply ipes. The tube 14 extends centrally of the tu ular Vmember 11 and part way upwardly into the latter, as shown, When the gas flowing l from the tube 14 is igniteda llame is produced which iscaused to become contacted by the-fuel issuing from the burner 7 for igniting the` fuel which thereafter burns 'at the burner 7 until the motor 9.is stopped.

The stopping and starting of the motor 9, for the purpose above stated, is Acontrolled through the medium of a switch Vrepresented generally at 22 and controlled by a thermostatdevice cooperating with the pilot light. The vswitch device. shown, and which ismerely illustrative of one form of well known vswitch which may be employed, comprises a block 23 of insulatingmaterial located, -and secured, in the hollow member 16,

-a pair of contacts 24 and 25 operatively connected in circuitwith the motor 9 and 'o'peratin 'whenhbridged across by a. cur- 'rent-con ucting member, to close .the circuit through themotor, a rocking'bridging member 26 for the contacts 24 and 25 and an operating' lever 27 for moving the member 26 into and -out of bridging position. The bridging member 26 is shown as formed of a shank 28 of insulating material: having journaled in one end thereof a roller device 29 .of current-conducting material which moves against the curved wall of an aperture 3L in the .body 23 and which is movable into and out of engagement with the lower ends -a cross-pin 36 extending at opposite.` .sides of the lever and to ether with the extremity ofthe lever at which' the pin 36 is located, extending into, and-being movable lengthwise of, a slot 37 in theshank of the member 26. The construction of the switch is such that the rocking ont the lever 27 on its pivot from the position shown in Fig. 2

to the positionshown in liig. 4, operates' to cause the bridging member to assume the position shown inFig. 4 in which position its bridging element 29 engages the contants 24 and 25 andcloses the circuit therebetween, and when this lever is reversely rocked from the position shown in lqig. 4

, tothe position shown inllig. 2 thel bridging member is moved to circuit-breaking position, represented in Fig. 2, it being understood that the spring 32 operates to cause the switch to function as a snap switch in the movement of the lever 27 in either dirction to cause thepin 36 to swing through, and beyond the plane in which the fulcrum 34 of the lever, and the roller-bridging element 29 extends.y

The lever 27 is operated through the mediumof a vertically-reciprocable rod 38 containing a slot 39 into which the outer end of the lever 27 extends, this lever, which is located in the member 16, being pivotally connected, at 40, with the' upper end of a link 41 the lower end of'which is pivotally connected' at 42 with the crank-arm 43 of a shaft 44 journaled in a wall of the member 16,' the outer end of this shaft being equipped with an operating lever 45 into the path of movement of which, 1 n the movement of the leverv to the left in Fig. 2, a stop 46 on the member '16 extends, the throw of I the lever 45 .being such that upon swinging this lever in one direction -or the other the switch will be opened or closed, depending upon the direction in which the lever is swung.

The thermostatic means hereinbefore referred to comprise the rod 38 which is connected at its upper end with a head 47, in the form of a disk which is centrally aperture, as represented at 48, and at which aperture it surrounds, 'and is vertically slidable on, the gas tube 14. rlhe lrod 38 is located to one side of the tube 14,- as shown, and the head 47, at a'point diametrically op osed to its connection with the vertically sli able on the gas tube 14. Lrllhe rod 38, is connected with the upper end of a coil spring 49, the lower end of which is connected with the supporting member 16, this spring operation to yieldingly resist upward movement of the parts controlledthereby from the position shown in Fig.' 2. The head 47 is provided with upwardlyextending, spaced apart, thermostat bars 50 which are each formed of strips 51 and 52 of metal having. dilerent coefficients of expansion, the material'of which the strips 51 are composed having a lower coecient of expansion than the material composing the strips 52. Y The bars 50, locatcdrespectively at opposite sides of the'tube 14, eXnd upwardly beyond the upper extremity of the latter, these bars being shown as connected with the head 47 to move therewith, by means of a ring 53 surrounding the upper reduced portion 54 et the head 47, and pins 55 extending through said ring and bars and into the reduced portion 54 of the head. 'lhmupper extremities of the bars 50 terminato in outwardl -bent portionsI 5G adapted to cooperate with lthe upper ends et a pair of vertically-disposed rods 57 located within the member 11 and rising from, and rigidly secured at their lower ends, to the supporting member 16, the head v47 being apertured at 58 to receive the rods 57 relative to which the head 47 is vertically movable. The parts just described are so constructed and arranged that when the structure comprising the head 47, bars 50, and rod 3S is raised to a position in which the shoulders 56 extend above the ends of the rods 57 and the bars 50 are vsubjected to the heat of the flame at the pilot, the bars will assume the outwardly-deflected position represented in this figure, in which position their outwardly-cxtending shoulder portions 56 extend directly above and thus in alignment with the respective rods 57 and in interlocked relation to the latter as shown in Fig. 4, due to the distorting eflect on these bars produced by the unequal expansion of the i strips 51 and 52 of which they are formed,

these bars extending in such outwardly diverging condition as long as the pilot remains ignited. Upon the pilot becoming extinguished, these bars quickly return to a position in which their projecting portions 56 are withdrawn out of alignment with the respective rods 57, as shown in Fig. 2.

The operation of the structure shown is as follows: Assuming that the parts of the structure are in the position shown in Figs. 1, 21, and 3, in which the switch controlling the motor 9 is open and consequently no fuel'yis being supplied to the burner 7, the operator starts the burner by opening the pilot tube 14 to the supply of gas furnished through the tube 21, as by opening a valve (not shown) interposed in the gas line and lill lne

llo

i itin the was at this tube and swinvinea b 7 r3 h t e lever 45 to theleft in Fig. 2 which results in the closing of the switch controlling the motor 9 which latter therelill) ramone upon starts into operation and supplies combustible fuel to the burner 7 which is.

- ignited by the 'flame at the pilotlight. In

movement of the lever 45, as stated, the projecting portions 56 of the thermostat are moved above the upper ends of the rods 57, the operator Vholdmgthe lever in the position ,-to which lit was swung, as -just stated, until the'bars 50 have become sufficiently heated to effect their; distortion to a position in which their shoulders 56 overlap the tops of the rods 57, whereupon the rod 38, together with the parts carried there by as hereinbefore described, lower to a position in which the projecting portions 56 bear against the upper ends of the rods 57 as shown in Fig. 4 and continue to support the parts just referred to in a position in which the switch controlling -themotor 91 position represented in Fig. 4 to the openposition represented in Fig'. 2. It will therefore be noted that vprovision is lmade tioned the thermostat as explained in confor automatically preventing the supplying of fuel to the burner 7, vunless the pilot light is. burning and the operator has posinection with Fi 4 of the drawings, and thus it is 4impossib e to accidentally fiood the burner with fuel.

By providing t-he thermostat mechanism as described the mechanism is caused to be capable of very quick action and is rendered very responsive lin action. Furthermore, the device presents practically no time lag,

so that practically as soon as the pilot light becomes extinguished, the controllingcircuit for the motoris opened.

The provision of the member 11 is of ad- .vantage inasmuch as it forms a shield' around the thermstatic element of the thermostat, yprotecting it against subjection to excessive heat produced in the combustion chamber 102 fired by the burner 7 the air in circulatingthrough the member 11, due to the forming of this member with openings at its upper and lower ends, also serving to` prevent excessive heating of the thermostat bars 50. Furthermore the provision for the circulation of air through the member 1 1 and against the thermostat bars 50 effects quick cooling of these bars should the pilot light become extinguished.

While I have illustrated and described a particular construction embodying my invention, I do not wish to be understood as intending to limit it thereto as the same may vbe variously modified and` altered without departing-from the spiritof the invention.

WhatI claim las new, and desire to secure,

by Letters Patent, is: f

1. In a thermostatieally controlled device the combination of a fuel-controlling device,

.element being positioned to be heated and Adevice and in its movementscontrolling said device and positioned to'be heated and when heated engaging said fixed member for preventing movement. of said movable member, and when the supplying of 'heat thereto is discontinueddisengaging from said fixed member topermit said movable member to move for affecting the condition of said fuel controlling device.

3. In a thermostatically-controlled device, the combination of a fuel-controlling device, relatively movable members one of which is fixed, the other ofsaid members being` bodily movable independently of said device and in its vmovements controlling said device and positioned to be heated and when heated engaging said fixed member for preventing movement ofsaid movable member, and

when the supplying of heat thereto is discontinued disengaging from said fixed member to permit said movable member to move for affecting the condition of said fuel controlling device, and means operating to move the movable one of said members when said last-referred-to member is released for movement.

. '4. In a thermostatically-controlled device,

'the combination-of a fuel-controlling device,

ing to move the movable one of said membersl when the latter is released for movement. A

` 5. In a thermostatically-controlled device, the combination of a fuel-controlling device, and relatively movable members one of which is fixed, the movable one of said members being a flexible thermostatic element movable bodily and in its movements controlling said device, said thermostatic member having a shoulder extending crosswise thereof and said thermostatic element being positioned to be heated, and when heated interlockingly engaging at its shoulder with' said fixed member for preventing movement bodily of said thermostatic clement and when thel supplying of heat thereto is discontinued disengaging at its shoulder from said fixed member -to permit said thermostatic element to move for affecting the condition of said fuel-controlling device.

.6. In a thermostatically-controlled device, the combination of a 'fuel-controlling device, relatively movable members one of which is fixed, the movable one of said members beinga fiexible thermostatic element movable bodily and inA its movements controlling said device, said thermostatic member having a shoulder extending crosswise Athereof and said thermostatic element being positioned to be heated, and when heated interlockingly engaging at its shoulder with said fixed member for preventing movement bodily of said thermostatic element and WhenV the supplying of heat thereto is d iscontinued disengaging at its shoulder from said fixed member to permit said theremostaticelemeint to move for affecting the condition of said fuel-controlling device, and means operating to move said thermostatic member when the latter is released for movement. l'

7. In a thermostatic device, the combination of a thermostat member having a shoulder extending crosswise thereof, a second member extending substantially parallel Awith said thermostatic member, one of said -members being fixed and the other thereof said thermostatic member when heated interlockingl 'engaging at itsshoulder with said secondl member and preventing movement of said movable member relative to said fixed member and when the supplying of heat to said thermostatic' member` is discontinued ldisengaging at its shoulder from said second member to permit movement of 8. In a thermostat device, the combination of a, thermostat member comprising thermostatic elements in the form of bars each formed of strips of material having different coeicients of expansion, a member supporting said bars adjacent one end thereof, the bars at their other'ends having to-be engaged by said projections When saidl bars are heated and holding said thermostat member 'against movement by said means and from which said projections disengage when the supplying of heat to said thermostat device is discontinued, to permit said means to actuate the latter, and an element controlled by said thermostat member.

9. In a thermostatically controlled device, the combinationiof a fuel-controlling device, and relatively `movable members one of which is fixed, the movable one of said members comprisinga plurality of fiexible thermostatic elements operatively connected together and movable bodily and in their movement controlling said device, said thermostatic elements being positioned to be heated and when heated independently engagingsaid fixed member for preventing movement of said thermostatic elements, and when the supplying of heat thereto is discontinued disengaging from said lastreferred-to member to permit saidthermostatic elements to move bodily for affecting the condition of said fuel-controlling device.

-10. In a furnace, the combination Aof a combustion chamber, a burner therein, the bottom of said chamber containing an upwardly extending passage open. at its opposite ends, said passage at its top being restricted thereby to form means shielding theinterior of said passage from the heat in said chamber, a pilot burner for said firstnamed burner and located in sai'd passage, and a thermostatic device controlling the supplying of fuel to said first-named burner, the thermostatic element of said device extending into said passage into the path'of the currents of` air circulating therethrough.

ll. In a furnace, the combination of a combustion chamber, a burner therein, an upwardly extending hollow member having its opposite ends open and opening at its upper end into the combustion chamber and at its lower end through the bottom of said combustion chambeiythe opening at the top ofl said hollow member being restricted thereby to form means for shielding the interior of said hollow member from the heat in said chamber, a pilot burner for said first-named burner and located in said `hollow member, and a thermostatic device eol 

